title: Synthesis of High Oxidation State Molybdenum Imido Heteroatom-Substituted Alkylidene Complexes.
abstract: Reactions between Mo(NAr)(CHR)(Me2Pyr)-(OTPP) (Ar = 2,6-i-Pr2C6H3, R = H or CHCMe2Ph, Me2Pyr = 2,5-dimethylpyrrolide, OTPP = O-2,3,5,6-Ph4C6H) and CH2=CHX where X = B(pin), SiMe3,N-carbazolyl,N-pyrrolidinonyl, PPh2, OPr, or SPh lead to Mo(NAr)(CHX)-(Me2Pyr)(OTPP) complexes in good yield. All have been characterized through X-ray studies (as an acetonitrile adduct in the case of X = PPh2). The efficiencies of metathesis reactions initiated by Mo(NAr)(CHX)(Me2Pyr)(OTPP) complexes can be rationalized on the basis of steric factors; electronic differences imposed as a consequence of X being bound to the alkylidene carbon do not seem to play a major role. Side reactions that promote catalyst decomposition do not appear to be a serious limitation for Mo=CHX species.
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
authors.forename: Erik M
authors.initials: EM
authors.lastname: Townsend
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Kilyanek
authors.forename: Richard R
authors.initials: RR
authors.lastname: Schrock
authors.forename: Peter
authors.initials: P
authors.lastname: Müller
authors.forename: Stacey J
authors.initials: SJ
authors.lastname: Smith
authors.forename: Amir H
authors.initials: AH
authors.lastname: Hoveyda